public class Ocean{
    public static void main(String[] args)
    {
        doSwim(new Human("贾斯汀"));
        doSwim(new Submarine("黄色一号"));
        doSwim(new Airplane("空军零号"));
        doSwim(new FlyingFish("甚平"));
    }

    static void doSwim(Swimmer swimmer){
        swimmer.swim();
    }
}